Hi.
According to Holy Trinity, God has three distinc person, So there must be two distinctions in God.
What is this distinction?
Well if you can accept that the nature of God exists and there is at least one Person corresponding to this divine nature then I think you can get the other two Persons. If God is pure Spirit, then He is capable of knowing and loving (those actions are the two highest actions of spirit: intellect and will). If God is absolutely simple, then He is perfect and as such does not need anything. All of creation adds nothing to God.
But if God is perfect, then how does He know anything perfectly? Creation is not an appropriate target of His knowing (it would only be finite knowledge). The only reality He could know perfectly would be Himself, being perfect as He is. If His knowledge of Himself is perfect, then His knowledge of Himself imparts no limitation on the nature of His self-image. Hence God’s act of knowing Himself begets a Second Person that is as much God as the First Person is. Contrast this with our knowing ourselves, like when we step back and say something like “oh what was I thinking when I was doing X?” We can have conceptions of ourselves but due to our limited natures these conceptions are purely mental and not as real as ourselves. This is the reason why the Nicene Creed says of the Second Person “begotten not made, consubstantial with the Father.”
Now that there are two Persons for the divine nature of God, what is an appropriate object of Their love? Not creation for reasons stated earlier. Instead, the First and Second Persons love each other Perfectly and pour their entire selves into the act of loving each other. Hence the generation of the Third Person of the Blessed Trinity who, like the other Persons, possesses the nature of God in its fullness. Again, a human analogy, flawed as it is, may be useful. The love of a husband and wife pour into a third person, namely the child. Thus, the Nicene Creed speaks of the Holy Spirit as “proceeding from the Father and the Son, Who with the Father and the Son is adored and glorified.”
